Most mobile devices are configured to receive removable Universal Integrated Circuit Cards (UICCs) that enable the mobile devices to access services provided by mobile network operators (MNOs). In particular, each UICC includes at least a microprocessor and a read-only memory (ROM), where the ROM is configured to store an MNO profile that the mobile device can utilize to register and interact with an MNO. Typically, a UICC takes the form of a small removable card (commonly referred to as a SIM card) that is configured to be inserted into a UICC-receiving bay included in a mobile device. In more recent implementations, however, UICCs are being embedded directly into system boards of mobile devices. Notably, these embedded UICCs (eUICCs) can provide several advantages over traditional, removable UICCs. For example, some eUICCs include a rewritable memory that can facilitate eSIM updates for accessing extended features provided by MNOs. eUICCs can also eliminate the need for UICC-receiving bays within mobile devices. The adoption of eUICCs, therefore, not only increases the flexibility of mobile devices, but also simplifies their design and frees up space for other components.
In some cases, it can be desirable to update an eUICC's firmware so that the eUICC can provide new or enhanced services to a user of the mobile device that includes the eUICC. However, firmware updates can be quite risky, as hardware components can become permanently inoperable when firmware updates are not carried out properly. This drawback is especially significant with respect to eUICCs as they are embedded within mobile devices and cannot be easily replaced if a firmware corruption were to occur.